Audacity from external drive....

I chose a specific location on my external hard drive to create all the temp files but Audacity is still eating all my local hard drive space and creating files…
Is there not a way to make sure everything is generated / used from my external?
If I leave the application open long enough, eventually I get a message saying that my hard disk is full.



What version number of Audacity are you using? Please see the pink panel at the top of the page.

In modern versions of Audacity you can change the Audacity temporary directory at Audacity > Preferences…, Directories section.

If it’s a USB external drive you should not use that for recordings. It may not be fast enough and may result in dropouts in the recording.


Audacity 2.1.1
That is how I specified the external drive; Audacity > Preferences…, Directories section.
It still eats space on my local drive.

Not only Audacity uses your system drive. Snow Leopard does too. And if you’re low on ram AND low on disk space on your startup drive, Snow Leopard’s caches could be eating up that valuable space, trying to swap between ram and disk.

And then there’s your browser, that stores gigabytes per day. And automatically erases it too. But it still needs to find a place on the startup disk.

It’s better to store as much data as you can on the external drive and free up some space on the startup drive. Rule of thumb says you need about 20% free, or OSX’s automatic defragmentation will stop working.

Recording to an external USB drive usually works well, if you only use that drive to record. As soon as you start using it to move lots of files around, fragmentation will sooner or later make it unusable for recording.

Obviously if you are saving Audacity projects to the hard drive or exporting to the hard drive, that will take space on the hard drive. Otherwise Audacity would only write settings to the hard drive, not audio data.

Are you using plugins? Certain Nyquist plugins write audio data to RAM, then if you are short of RAM you will get that data held in memory “swapped out” to the hard drive instead, as cyrano describes.

Regardless, USB hard disk drives (if that is what jgcalifornia has) are much slower than a built-in hard drive. And if the drive uses a FAT or NTFS file system, it will be prone to defragment.


While I agree USB drives are slower and FAT is prone to fragmentation, as OSX doesn’t defrag FAT file systems, it’s not drive speed that affects recording most. NTFS probably isn’t in the picture, as a standard OSX install can’t write to an NTFS drive.

It’s the drive’s tendency to align heads every now and then. Years ago, there were drives that were “AV” labelled. They had different firmware to avoid re-aligning heads while writing.

These days, most drives are fast enough and have enough buffer ram to avoid that completely.

Another problem is some USB drives have USB-to-SATA controllers that aren’t buffered at all, or with a very small buffer. In certain circumstances, these buffers work against the on-disk buffers. Something you won’t see from good manufacturers, but especially cheap portable USB powered “portable” drives sometimes exhibit that behaviour. It’s not that the controller is bad, or the drive is bad, it’s just an unfortunate combination of the two.

Personally, I never buy USB powered drives. The power draw is enough to make most USB audio interfaces noisy on most computers.